This invention relates generally to a machine for severing standing crops from the ground to initiate a harvesting process and, more particularly, to a rotary disc cutterbar having a preselected number of transversely oriented, electric motor powered rotatable discs with knives mounted thereon to sever standing crop by an impact action upon rotation of the discs.
Typical disc cutterbars used in agriculture include an elongated housing containing a train of meshed idler and drive spur gears, or a main power shaft or series of power shafts coupled by respective bevel gear sets, for delivering power to respective drive shafts for modular cutterheads spaced along the length of the cutterbar. The cutterheads each comprise a cutting disc including diametrically opposed cutting blades (though configurations with three or more blades are known) and having a hub coupled to an upper end of a drive shaft, the lower end of the drive shaft carrying a spur gear in the case where a train of meshed spur gears is used for delivering power, and carrying a bevel gear of a given one of the bevel gear sets in the case where a main power shaft is used. For background information on the structure and operation of some typical disc cutterbars, reference is made to U.S. Pat. No. 5,996,323, issued to Campbell, the descriptive portions thereof being incorporated herein in full by reference.
Mechanical drivetrains are typically used to direct power to each modular cutterhead on the cutterbar. The power transmission requirement and shock loadings resulting from cutter impact with rocks and other obstructions generally result in over-designed drivetrain parts capable of handling loads far greater than the loadings on an isolated rotary disc cutterhead. The additional strength in a modular cutterhead results in greater weight for the cutterbar and greater manufacturing costs. Rotation of the modular cutterheads is interlocked so that all cutterheads rotate at the same speed and at pre-determined relative directions.
Modular cutterhead designs allow an individual damaged cutterhead to be removed and replaced without affecting adjacent cutterhead modules. The modular design contains debris from gear failures within an individual module oil sump and reduces debris contamination of adjacent modules. However, replacing a single damaged cutterhead module is not an insignificant task requiring significant disassembly of the cutter bar in order to remove a damaged cutterhead from the cutterbar driveline because of intermediate drive shafts disposed between adjacent modules to transfer power laterally along the cutterbar.
It would be advantageous to have a cutterhead module powered by an electric motor that would reduce the drivetrain and module mounting complexity. Further advantages would be realized by a lighter weight electric cutterbar for an agricultural harvester. Still further advantages would be realized in an electric cutterhead module for a transverse cutterbar that would enable relative variations in cutterhead speed or rotational direction to improve cut crop flow across the cutterbar.